If you live in a dry climate there’s no doubt that you’ve experienced static electricity. It’s the force that causes your socks to stick together in the dryer, makes your hair difficult to comb and gives you an unpleasant shock when you touch a metal object after walking across the carpet. It can literally be a hair-raising experience!
The effects of static electricity can be uncomfortable for human beings but they can be downright deadly for electronic components. Today’s electronics rely upon integrated circuits, and integrated circuits consist of extraordinarily tiny components manufactured on a tiny silicon chip. These microscopic size devices are vulnerable to the effects of static electric shocks. This is especially true when the components are loose and not mounted in a circuit board, as the copper traces on the circuit board tends to dissipate static electricity to some degree. But all electronic components whether mounted on a board or not can be harmed by static electricity.
If you’re going to work with electronics you need to be able to create a static-free environment and practice safe working methods so that you don’t harm your precious components. Read on for some advice on doing exactly that.
Establish a Static-Free Environment
The first step in defending against static electricity is simply not to create it in the first place.
Static electricity is more prevalent in dry environments so adding humidity to your environment can go a long way toward preventing static electricity from building up. The amount of humidity that you need to add is dependent upon your climate of course and if you live in a humid climate you’re already at an advantage compared to those who live in desert environments.
Keep in mind that there are some climates where the humidity changes seasonally, for example the area I live in is quite humid in the summer yet quite dry in the winter so I need to take additional precautions when working in the winter months.
A humidifier is the best way to add humidity to your environment, it will be good for your electronic components and will also make you more comfortable as well. There are several varieties of humidifiers such as ultrasonic, cool mist and conventional heater devices. Each of them has their merits and they are usually rated by the number of cubic feet or cubic meters that they can humidify.
When using a humidifier it is important to keep the device clean. Most humidifiers have a wick or a filter that needs to be periodically cleaned, in some devices this also needs to be replaced occasionally . Failing to keep the humidifier clean can actually be a health hazard, so make certain you follow the manufacturer’s instructions.
In addition to a humidifier you should look at your work area and see if there are things that you can do to reduce the buildup of static electricity.
An anti-static mat is an excellent addition to your workbench, these devices are made for industrial areas and also for computer workstations. The mat that I have on my work bench is inexpensive and in addition to keeping static down provides a slight bit of padding which is also nice for my electronic components. Anti-static mats need to be grounded so that they can bleed off the static electricity, all of these devices contain an internal resistor to keep you safe should you accidentally come into contact with line voltage while working over the mat.
You can also make your own anti-static surface out of any conductive material that you ground through a 1 to 10 megohm resistor. It is vital that you use the resistor, never ground it directly!
If you keep your parts in plastic cabinets (as I do) you might consider lining the cabinets with an anti-static material. This material is available at many Industrial Supply and electronic stores and is designed specifically to reduce the buildup of static electricity around electronic components. I lined my parts drawers with anti-static material to insure that my precious components will not be accidentally damaged.
If your floor is carpeted you might also consider an anti-static floor mat. These devices are available at office supply stores and like the anti-static desk pad they come with a grounding wire. Most are made of a hard conductive plastic.
There is another variety of anti-static mat that is also cushioned, so it serves the function of both reducing static electricity and making your work experience more pleasant by reducing fatigue. These can be rather expensive but if you do a lot of work standing at your your workbench they can be worth it in the long run.
Handle with Care
Now that you’ve created an anti-static environment you also should use certain precautions when handling electronic components.
First of all watch what you wear. The beautiful sweater you got last Christmas may look wonderful but it also will hold an incredibly large static charge. You can buy specific anti static clothes and shoes but in most cases it would just sufficed to wear clothes that aren’t made of wool or other static inducing materials. 3M Scotchgard and similar products can also reduce the static holding properties of many fabrics.
Short sleeve shirts are ideal as they won’t build up static on your arms, Short sleeves are also a good idea if you are working around power tools, as you won’t be able to catch your sleeve inadvertently and cause an even more serious accident.
An anti-static wrist strap is commonly used to bleed off static electricity. these are inexpensive devices that wrap around your wrist and have a coiled cord which is grounded. As with the other anti-static devices the court is grounded through a 10 megohm resistor, the last thing you ever want to do is tie your arm directly to ground as you could be severely injured or even killed should you come into contact with high voltages!
You can buy an anti-static wrist strap it just about any electronics store or order one online. You could even make your own but again make certain that you ground it through a large value resistor.
On my workbench I’ve added some grounding points (standard banana jacks) to attach my anti-static strap, they are conveniently located to keep the straps wire from getting entangled in my workbench equipment.
Finally, many electronic components and circuit boards such as your brand-new Arduino and Raspberry Pi come packaged an anti-static envelope. It’s a good idea to keep these components in the envelope until you actually have to use them. This will further reduce the chance of static electricity harming your devices.
By taking some sensible precautions with both your environment and your work habits you can pretty well eliminate the chance of static electricity harming your components. So fight back – don’t get zapped by static electricity!